STDEV(cells) - standard deviation of a sample population; measures how much values vary from the mean

You can type these functions straight into the cells starting with the equal sign, e.g. type =stdev(A1:A10). Capitalisation is not important. Replace "cells" in the above list with the cells to be used for the calculation. Cells can be specified by clicking or typing. You can specify a range of cells by stating the (top) left and the (bottom) right cell, e.g. type A1:A10 (10 cells) or A1:B10 (2x10cells). Alternatively, you can enumerate cells using commas as separators, e.g. A1,A3,A5. If you want to prevent automatic change of the column or row when copying formulas, use the dollar sign, e.g. $A1 will keep the column the same while A$1 will prevent a change in the row number.

Student t test

Excel's Student's t test is based on the function TTEST(). Watch out to correctly specify the tails and type parameters. If in doubt use: tails 2, type 3. This is the most stringent setting.

You can see how tails and type affect the values. Note this data is not paired; the last test should not be applied here and is just given for completeness. In most experiments you will be comparing unpaired data, unless you follow the same system in different conditions. For example, cells at 1h, same cells at 2h. Note that 2 tails, unequal SD (starred) gives the highest value, which means it is the most stringent test.

Result: The data series are significantly different from each other with p < 0.001.